Date   : Sun, 05 Jun 2005 14:30:15 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: Re: Assembly Language Square Root

"F. Haroon" <haroonnet2002@...> wrote:
> This program gives me a lot of garble when testing...
 
Works here:
----8<----
>LIST
   10PROCasm:PROCtest:END
   20:
   30DEFPROCasm
   40DIM mc% &100
   50in=&70:out=&72
   60FOR P=0 TO 1:P%=mc%:[OPT P*2
   70.sqr                            :\ On entry, !in=input value
   80LDY #1:STY out+0:DEY:STY out+1  :\ Initialise out to first subtrand
   90.sqr_loop                       :\ Repeatedly subtract increasing
  100SEC                             :\   odd numbers until in<0
  110LDA in+0:TAX:SBC out+0:STA in+0 :\ in=in-subtrand, remainder in X
  120LDA in+1:SBC out+1:STA in+1
  130BCC sqr_done                    :\ in<0, all done
  140INY                             :\
  150LDA out+0:ADC #1:STA out+0      :\ step +2 to next odd number
  160BCC sqr_loop                    :\ no overflow, subtract again
  170INC out+1:BNE sqr_loop          :\ INC high byte and subtract again
  180.sqr_done
  190STY out+0:STX out+1             :\ out?0=root, out?1=remainder
  200RTS
  210]NEXT:ENDPROC
  220:
  230DEFPROCtest
  240FOR A%=1 TO 65535:!in=A%:CALL sqr:PRINTA%,out?0,out?1:NEXT
  250ENDPROC
>RUN
         1         1         0
         2         1         1
         3         1         2
         4         2         0
         5         2         1
         6         2         2
         7         2         3
         8         2         4
         9         3         0
        10         3         1
        11         3         2
        12         3         3
        13         3         4
        14         3         5
        15         3         6
        16         4         0
        17         4         1
        18         4         2
        19         4         3
        20         4         4
        21         4         5
        22         4         6
        23         4         7
        24         4         8
        25         5         0
        26         5         1
        27         5         2
        28         5         3
        29         5         4
        30         5         5
        31         5         6
        32         5         7
        33         5         8
        34         5         9
        35         5        10
        36         6         0
        37         6         1
        38         6         2
        39         6         3
        40         6         4
        41         6         5
        42         6         6
        43         6         7
        44         6         8
        45         6         9
        46         6        10
        47         6        11
        48         6        12
        49         7         0
        50         7         1
        51         7         2
        52         7         3
        53         7         4
        54         7         5
        55         7         6
        56         7         7
        57         7         8
        58         7         9
        59         7        10
        60         7        11
        61         7        12
        62         7        13
        63         7        14
        64         8         0
        65         8         1
        66         8         2
        67         8         3
        68         8         4
        69         8         5
        70         8         6
        71         8         7
        72         8         8
        73         8         9
        74         8        10
        75         8        11
        76         8        12
        77         8        13
        78         8        14
        79         8        15
        80         8        16
        81         9         0
        82         9         1
        83         9         2
        84         9         3
        85         9         4
        86         9         5
        87         9         6
        88         9         7
        89         9         8
        90         9         9
        91         9        10
        92         9        11
        93         9        12
        94         9        13
        95         9        14
        96         9        15
 
Escape at line 240
>*SPOOL
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
HADFS System Resources - http://mdfs.net/Software/HADFS